Add functions to ClientConn so it satisfies an interface for generated code (#1599)

call.go

@@ -125,16 +125,23 @@ func sendRequest(ctx context.Context, dopts dialOptions, compressor Compressor,
 	return nil
 }
 
-// Invoke sends the RPC request on the wire and returns after response is received.
-// Invoke is called by generated code. Also users can call Invoke directly when it
-// is really needed in their use cases.
-func Invoke(ctx context.Context, method string, args, reply interface{}, cc *ClientConn, opts ...CallOption) error {
+// Invoke sends the RPC request on the wire and returns after response is
+// received.  This is typically called by generated code.
+func (cc *ClientConn) Invoke(ctx context.Context, method string, args, reply interface{}, opts ...CallOption) error {
 	if cc.dopts.unaryInt != nil {
 		return cc.dopts.unaryInt(ctx, method, args, reply, cc, invoke, opts...)
 	}
 	return invoke(ctx, method, args, reply, cc, opts...)
 }
 
+// Invoke sends the RPC request on the wire and returns after response is
+// received.  This is typically called by generated code.
+//
+// DEPRECATED: Use ClientConn.Invoke instead.
+func Invoke(ctx context.Context, method string, args, reply interface{}, cc *ClientConn, opts ...CallOption) error {
+	return cc.Invoke(ctx, method, args, reply, opts...)
+}
+
 func invoke(ctx context.Context, method string, args, reply interface{}, cc *ClientConn, opts ...CallOption) (e error) {
 	c := defaultCallInfo()
 	mc := cc.GetMethodConfig(method)

rpc_util.go

@@ -439,19 +439,19 @@ func Errorf(c codes.Code, format string, a ...interface{}) error {
 	return status.Errorf(c, format, a...)
 }
 
-// SupportPackageIsVersion3 is referenced from generated protocol buffer files.
-// The latest support package version is 4.
-// SupportPackageIsVersion3 is kept for compatibility. It will be removed in the
-// next support package version update.
-const SupportPackageIsVersion3 = true
-
-// SupportPackageIsVersion4 is referenced from generated protocol buffer files
-// to assert that that code is compatible with this version of the grpc package.
+// The SupportPackageIsVersion variables are referenced from generated protocol
+// buffer files to ensure compatibility with the gRPC version used.  The latest
+// support package version is 5.
 //
-// This constant may be renamed in the future if a change in the generated code
-// requires a synchronised update of grpc-go and protoc-gen-go. This constant
-// should not be referenced from any other code.
-const SupportPackageIsVersion4 = true
+// Older versions are kept for compatibility. They may be removed if
+// compatibility cannot be maintained.
+//
+// These constants should not be referenced from any other code.
+const (
+	SupportPackageIsVersion3 = true
+	SupportPackageIsVersion4 = true
+	SupportPackageIsVersion5 = true
+)
 
 // Version is the current grpc version.
 const Version = "1.8.0-dev"

stream.go

@@ -94,15 +94,23 @@ type ClientStream interface {
 	Stream
 }
 
-// NewClientStream creates a new Stream for the client side. This is called
-// by generated code.
-func NewClientStream(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, opts ...CallOption) (_ ClientStream, err error) {
+// NewStream creates a new Stream for the client side. This is typically
+// called by generated code.
+func (cc *ClientConn) NewStream(ctx context.Context, desc *StreamDesc, method string, opts ...CallOption) (ClientStream, error) {
 	if cc.dopts.streamInt != nil {
 		return cc.dopts.streamInt(ctx, desc, cc, method, newClientStream, opts...)
 	}
 	return newClientStream(ctx, desc, cc, method, opts...)
 }
 
+// NewClientStream creates a new Stream for the client side. This is typically
+// called by generated code.
+//
+// DEPRECATED: Use ClientConn.NewStream instead.
+func NewClientStream(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, opts ...CallOption) (ClientStream, error) {
+	return cc.NewStream(ctx, desc, method, opts...)
+}
+
 func newClientStream(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, opts ...CallOption) (_ ClientStream, err error) {
 	var (
 		t      transport.ClientTransport